By popular demand, here is another alternate ending for DH. Some quick background for this one: Draco has turned traitor against Voldemort.
Draco Malfoy watched, pulse racing, as Harry and Voldemort circled each other. He didn't hear a word they said; how could he when his life hung in the balance? All he heard was his own thoughts: If Harry wins, I'm okay. If the Dark Lord wins, I'm screwed.
Suddenly, Harry's wand--no, that was Draco's wand, wasn't it?--flew out of his hand midsentence. Voldemort smirked.
"Expelliarmus can be used nonverbally, Harry Potter. Unfortunately, this important lesson seems to have eluded you...a lesson, I am not sorry to say, you will never have the chance to learn..."
Draco's thoughts changed. Oh crap...I'm screwed! I'm dead, I'm dead, I'm dead, I'm dead...
Suddenly, Neville Longbottom nudged him with his elbow, jerking him from what he was sure would be his last thoughts.
"I've still got the Hat, Drake!" he whispered.
"What the hell--"
"Just trust me! And distract You-Know-Who!"
"Wha--how am I supposed to do that?"
"Use your imagination!" With that, Neville abandoned Draco and disappeared into the crowd. Draco hesitated only a few seconds before a plan manifested in his mind. He wasted no time in putting it into action.
"Hey!" he shouted. "Moldy-Shorts!"
Voldemort turned, red eyes widening at the realization that one of his Death Eaters had just called him Moldy-Shorts. "You dare..."
"Yeah, I dare!" Neville was next to Harry now, handing him the Sorting Hat. He had no idea how this would keep Voldemort from killing them all, but Neville usually knew what he was doing, so Draco continued with his plan.
"And you know what else I dare?" he continued. He answered his own question by turning, bending over, and yanking his pants down to his ankles. Voldemort's jaw dropped, and the crowd drew in a collective gasp. Draco just smirked, but it quickly faded as Voldemort raised his wand...
...and fell forward to reveal Harry Potter standing behind him, holding the bloody Sword of Gryffindor, grinning from ear to ear. Come to think of it, the entire Order of the Phoenix and the DA were grinning as well. Draco, caught up in the trend, laughed and pulled his pants up. Harry walked over, laughing, and they high-fived.
"I can't believe you mooned him!"
The grin wouldn't leave Draco's face. "You kidding? I've always wanted to do that!"
Their laughter spread across the Great Hall like wildfire.